In collaboration with Matt Warman at Case Western Reserve University, Cleveland OH, we identified mutations in a gene previously known as megakaryocyte growth and stimulating factor, which causes the disease camptodactyly-arthropay-coxa vara-pericarditis (CACP) syndrome. This is an autosomal recessive disease with synovial hyperplasia as the basic underlying defect which leads to several clinical phenotypes, mainly loss of proper joint growth and function. We have made a mouse knockout construct and are currently studying these animals to see whether or not we can replicate the human phenotype in mice. This will allow us to better understand joint development and will also allow us to identify the basic molecular components responsible for CACP.